Synthesis of ZSM-12 zeolite

ABSTRACT

There is disclosed a process for preparing a ZSM-12 crystalline zeolite wherein the organic template used in the synthesis has the formula: ##STR1## wherein n=4-10. The template, designated herein DABCO-C n  -diquat, is obtained from a dihalide salt of the template or from a hydroxide thereof.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of copending U.S. applicationSer. No. 490,082, filed Apr. 29, 1983 now U.S. Pat. No. 4,482,531, theentire disclosure of which is expressly incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a novel method of synthesis of ZSM-12 zeolite.

2. Discussion of Prior Art

Zeolitic materials, both natural and synthetic, have been demonstratedin the past to have catalytic properties for various types ofhydrocarbon conversion. Certain zeolitic materials are ordered, porouscrystalline aluminosilicates having a definite crystalline structure asdetermined by X-ray diffraction, within which there are a large numberof smaller cavities which may be interconnected by a number of stillsmaller channels or pores. These cavities and pores are uniform in sizewithin a specific zeolitic material. Since the dimensions of these poresare such as to accept for adsorption molecules of certain dimensionswhile rejecting those of larger dimensions, these materials have come tobe known as "molecular sieves" and are utilized in a variety of ways totake advantage of these properties.

Such molecular sieves, both natural and synthetic, include a widevariety of positive ion-containing crystalline aluminosilicates. Thesealuminosilicates can be described as having a rigid three-dimensionalframework of SiO₄ and AlO₄ in which the tetrahedra are cross-linked bytheir sharing of oxygen atoms whereby the ratio of the total aluminumand silicon atoms to oxygen atoms is 1:2. The electrovalence of thetetrahedra containing aluminum is balanced by the inclusion in thecrystal of a cation, for example an alkali metal or an alkaline earthmetal cation. This can be expressed by the relationship of aluminum tothe cations, wherein the ratio of aluminum to the number of variouscations, such as Ca/2, Sr/2, Na, K, Cs or Li, is equal to unity. Onetype of cation may be exchanged either entirely or partially withanother type of cation utilizing ion exchange techniques in aconventional manner. By means of such cation exchange, it has beenpossible to vary the properties of a given aluminosilicate by suitableselection of the cation. The spaces between the tetrahedra are occupiedby molecules of water prior to dehydration.

Prior art techniques have resulted in the formation of a great varietyof synthetic aluminosilicates. The aluminosilicates have come to bedesignated by letter or other convenient symbols, as illustrated byzeolite A (U.S. Pat. No. 2,882,243), zeolite X (U.S. Pat. No.2,882,244), zeolite Y (U.S. Pat. No. 3,130,007), zeolite ZK-5 (U.S. Pat.No. 3,247,195), zeolite ZK-4 (U.S. Pat. No. 3,314,752), zeolite ZSM-5(U.S. Pat. No. 3,702,886), zeolite ZSM-11 (U.S. Pat. No. 3,709,979),zeolite ZSM-12 (U.S. Pat. No. 3,832,449), zeolite ZSM-20 (U.S. Pat. No.3,972,983), zeolite ZSM-23 (U.S. Pat. No. 4,076,842), ZSM-35 (U.S. Pat.No. 4,016,245), and ZSM-38 (U.S. Pat. No. 4,046,859).

The SiO₂ /Al₂ O₃ ratio of a given zeolite is often variable. Forexample, zeolite X can be synthesized with SiO₂ /Al₂ O₃ ratios of from 2to 3; zeolite Y, from 3 to about 6. In some zeolites, the upper limit ofthe SiO₂ /Al₂ O₃ ratio is unbounded. ZSM-5 is one such example whereinthe SiO₂ /Al₂ O₃ ratio is at least 5, up to infinity. U.S. Pat. No.3,941,871, now U.S. Pat. No. Re. 29,948, the entire contents of whichare incorporated herein by reference, discloses a porous crystallinesilicate zeolite made from a reaction mixture contining no deliberatelyadded alumina in the recipe and exhibiting the X-ray diffraction patterncharacteristic of ZSM-5 type zeolites. U.S. Pat. Nos. 4,061,724,4,073,865 and 4,104,294, the entire contents of all three patents beingincorporated herein by reference, describe crystalline silicates ororganosilicates of varying alumina and metal content.

ZSM-12 has previously been synthesized in the presence of tetraethylammonium cations, used as the organic template (see, U.S. Pat. No.3,832,449, the entire contents of which are incorporated herein byreference).

It has now been found that ZSM-12 zeolite can also be prepared in thepresence of a new organic template described below.

SUMMARY OF THE INVENTION

ZSM-12 zeolite is prepared in accordance with this invention in aprocess comprising preparing a reaction mixture comprised of sources ofan alkali or alkaline earth metal, alumina, silica, RN⁺ and water, andhaving the following composition, in terms of mole ratios of oxides:

                  TABLE I                                                         ______________________________________                                                                       Most                                                        Broad   Preferred Preferred                                      ______________________________________                                        OH.sup.- /YO.sub.2                                                                           0.10-0.40 0.15-0.30 0.17-0.25                                  RN.sup.+ /(RN.sup.+  + M)                                                                    0.20-0.95 0.28-0.90 0.30-0.50                                  H.sub.2 O/OH.sup.-                                                                             20-300    50-200    80-150                                   YO.sub.2 /W.sub.2 O.sub.3                                                                      40-5000   60-500    90-300                                   ______________________________________                                    

wherein Y is silicon or germanium, M is an alkali or alkaline earthmetal, W is aluminum or gallium and RN⁺ is a functional group, of whichthere are two in the organic cation, the organic cation being designatedherein DABCO-C_(n) -diquat or (RN)₂ ²⁺, and derived from a halogen saltor hydroxide of DABCO-C_(n) -diquat and maintaining the mixture atcrystallization conditions until crystals of ZSM-12 are formed.Thereafter, the crystals are separated from the liquid and recovered.Typical reaction conditions consist of heating the foregoing reactionmixture to a temperature of from about 80° C. to 180° C. for a period oftime of from about 6 hours to 150 days. A more preferred temperaturerange is from about 150° C. to 170° C. with the amount of time at atemperature in such range being from about 5 days to 30 days. Thehalogen salt of DABCO-C_(n) -diquat is obtained by reacting two (2)molecules of diazabicyclo(2,2,2)octane (DABCO--a registered trademark ofAir Products and Chemicals, Inc.), also known in the art astriethylenediamine (TED), with one (1) molecule of dihalo-n-alkane ofthe formula:

    X--(CH.sub.2).sub.n --X

wherein X is a halogen and n is 4-10. The hydroxide form of DABCO-C_(n)-diquat is prepared by converting the halogen salt of DABCO-C_(n)-diquat in a conventional manner. When either the halogen salt or thehydroxide of DABCO-C_(n) -diquat are dissolved in an aqueous reactionmixture used to synthesize ZSM-12 zeolite, they dissociate into thecation (RN)₂ ²⁺ and the respective anion. The cation has the formula:##STR2## wherein n is 4-10. This functional group is the organictemplate of the present invention.

In the process of this invention, ZSM-12 is preferentially synthesizedfrom a mixture containing a high silica to alumina ratio, for examplemore than about 50 to 1, at crystallization temperatures of about 160°C.

The digestion of the gel particles is carried out until crystals form.The solid product is separated from the reaction medium, as by coolingthe whole to room temperature, filtering and water washing.

The foregoing product is dried, e.g., at 230° F., for from about 16 to24 hours. Of course, milder conditions may be employed if desired, e.g.,room temperature under vacuum.

ZSM-12 is preferably formed as an aluminosilicate. The composition canbe prepared utilizing materials which supply the appropriate oxide. Suchcompositions include, for an aluminosilicate, sodium aluminate, alumina,sodium silicate, silica hydrosol, silica gel, silicic acid, sodiumhydroxide and DABCO-C_(n) -diquat compounds, e.g., DABCO-C_(n) -diquatdibromide. It will be understood that each oxide component utilized inthe reaction mixture for preparing a member of the ZSM-12 zeolite can besupplied by one or more initial reactants and they can be mixed togetherin any order. For example, sodium oxide can be supplied by an aqueoussolution of sodium hydroxide, or by an aqueous solution of sodiumsilicate; DABCO-C_(n) -diquat can be supplied by DABCO-C_(n) -diquatdibromide or by DABCO-C_(n) -diquat hydroxide. The reaction mixture canbe prepared either batchwise or continuously. Crystal size andcrystallization time of the ZSM-12 composition will vary with the natureof the reaction mixture employed.

DETAILED DESCRIPTION OF THE INVENTION

ZSM-12 compositions can be identified in terms of mole ratios of oxidesas follows:

    (1.0±0.4)L.sub.2/m O:W.sub.2 O.sub.3 :(40-5000)YO.sub.2 :zH.sub.2 O

wherein L is a cation, m is the valence thereof, W is aluminum orgallium, Y is silicon or germanium and z is from 0 to 60. The cation Lcan be any cation present in the ZSM-12 composition in theas-synthesized form or exchanged thereinto after the synthesis, e.g.,alkali or alkaline earth metal, ammonium, hydrogen or the DABCO-C_(n)-diquat cation. It should be noted that in the analysis of the zeolitethe value of nitrogen can exceed 1.4 by reason of occluded organicnitrogen compound in the crystalline product.

As mentioned above, DABCO-C_(n) -diquat dihalide is obtained by reactingtwo (2) molecules of diazabicyclo(2,2,2)octane (DABCO) with one (1)molecule of the dihalo-n-alkane of the formula:

    X--(CH.sub.2).sub.n --X

wherein X is a halogen, e.g., fluorine (F), chlorine (Cl), bromine (Br)or iodine (I), preferably bromine or iodine, and n is 4-10. The halogenderivative of DABCO-C_(n) -diquat may be used to introduce the organictemplate in the ZSM-12 synthesis and its structure, in theas-synthesized form, is as follows: ##STR3## wherein X and n are asdefined above. Each of the two DABCO molecules used in the synthesis ofthis compound has only one of its nitrogen atoms quaternized, andtherefore carrying a positive charge. The halogen derivative ofDABCO-C_(n) -diquat is used as the ZSM-12 synthesis template. It issoluble in water and forms a stable solution of cations having theformula: ##STR4## and halogen anions. It will be apparent to thoseskilled in the art that the halogen form of DABCO-C_(n) -diquat can beconverted into the hydroxide form thereof by any conventional ionexchange techniques, e.g., those exemplified in U.S. Pat. Nos.3,140,249, 3,140,251 and 3,140,251, the entire contents of all of whichare incorporated herein by reference. Either the halogen or thehydroxide form of the DABCO-C_(n) -diquat can then be used in the ZSM-12synthesis, because, as will be apparent to those skilled in the art,either of the two forms of the compound will dissociate in an aqueoussolution into the respective cations and anions.

The synthesis of the halogen salt of DABCO-C_(n) -diquat is conductedwith constant stirring in methanol at the temperature of about 45°-55°C. in the manner described in detail by T. P. Abbiss and F. G. Mann inTriethylenediamine(1,4-Diazabicyclo-[2,2,2]octane) andHexaethylenetetramine. The Interaction of Triethylenediamine andDibromomethane, 1,2-Dibromoethane, and 1,3-Dibromopropane. JOURNAL OFTHE CHEMICAL SOCIETY, published by Chemical Society (London, 1964), pp2248-2254, the entire contents of which are incorporated herein byreference. If desired, the halogen salt can be converted to thehydroxide form of the DABCO-C_(n) -diquat in any conventional manner.

The DABCO-C_(n) -diquat, in its halogen or hydroxide form, is then usedto synthesize ZSM-12 zeolite in the reaction mixture of Table 1.

In a preferred embodiment of ZSM-12 synthesis, W is aluminum, Y issilicon, X is Br or I, M is sodium or potassium and the silica/aluminaratio is 60-500. In the most preferred embodiment M is sodium, W isaluminum, Y is silicon, X is Br, n=5 and the silica to alumina ratio is90-300.

ZSM-12 zeolites produced in the process of this invention possess adefinite distinguishing crystalline structure whose X-ray diffractionpattern shows the following significant lines:

                  TABLE II                                                        ______________________________________                                                            RELATIVE INTENSITY                                        INTERPLANAR SPACING D(A)                                                                          100 I/I                                                   ______________________________________                                        11.9 ± 0.2       W                                                         10.1 ± 0.2       W                                                         4.71 ± 0.1       W                                                         4.26 ± 0.08      VS                                                        3.96 ± 0.08      W                                                         3.88 ± 0.07      S                                                         3.46 ± 0.07      M                                                         3.38 ± 0.07      M                                                         3.20 ± 0.06      W                                                         3.07 ± 0.05      W                                                         2.52 ± 0.03      W                                                         ______________________________________                                    

These values were determined by standard techniques using the PhilipsAPD-3600 diffraction system. The radiation was the K-alpha doublet ofcopper, and a spectrometer equipped with a scintillation detector,interfaced with a computer system and disc drive was used. The data wascollected by step-scanning at intervals of 0.02 degrees 2 theta at acounting time of 2 seconds per step. The peak heights, I, and thepositions as a function of 2 times theta, where theta is the Braggangle, were derived by computer techniques using the second derivativemethod. From these, the relative intensities, 100 I/I_(o), where I_(o)is the intensity of the strongest line or peak, and D(obs.), theinterplanar spacing in A, corresponding to the recorded lines, werecomputed. In Table II the relative intensities are given in terms of thesymbols VS=very strong, S=strong, M=medium and W=weak. It should beunderstood that this X-ray diffraction pattern is characteristic of allthe species of ZSM-12 compositions. Ion exchange of the sodium ion withcations reveals substantially the same pattern with some minor shifts ininterplanar spacing and variation in relative intensity. Other minorvariations can occur depending on the silicon to aluminum ratio of theparticular sample, as well as if it has been subjected to thermaltreatment.

The X-ray diffraction pattern of ZSM-12 can be indexed in the monoclinicsystem with lattice parameters having the following values:

a=24.9±0.4A.

b=5.0±0.1A

c=12.15±0.2A. and the angle

β=107.7°±1°.

ZSM-12 zeolites are useful in cracking and hydrocracking and in otherpetroleum refining processes indicating the unique catalyticcharacteristics of this family of zeolites. The latter processes includereduction of pour point of paraffinic charge stocks; isomerization ofn-paraffins and naphthenes; polymerization of compounds containing anolefinic or acetylinic carbon to carbon linkage, such as isobutylene,butene-1 and butadiene; reforming, alkylation, isomerization ofpolyalkyl substituted aromatics, e.g., ortho-xylene anddisproportionation of aromatics, such as toluene to provide a mixture ofbenzene, xylenes and higher methylbenzenes; dehydration, hydration,dehydrogenation. The ZSM-12 catalysts have exceptional high selectivityand under the conditions of hydrocarbon conversion provide a highpercentage of desired products relative to total products compared withknown zeolitic hydrocarbon conversion catalysts.

ZSM-12 zeolites, as indicated above, are also useful in catalyticprocesses, such as catalytic cracking of hydrocarbons and hydrocracking.In addition to the thermal stability of this family of zeolites underthese conditions, they catalyze conversion of chargestocks to materialswhich are of greater economic value. The ability to be physically stableunder high temperatures and/or in the presence of high temperature steamis extremely important for a cracking catalyst. However, this crackingis accompanied by a number of complex side reactions, such asaromatization, polymerization, alkylation and the like. As a result ofthese complex reactions, a carbonaceous deposit is laid down on thecatalyst which is referred to by petroleum engineers as "coke." Thedeposit of coke on the catalyst tends to seriously impair the catalystefficiency for the principal reaction desired and to substantiallydecrease the rate of conversion and/or the selectivity of the process.Thus, it is common to remove the catalyst after coke has been depositedthereon and to regenerate it by burning the coke in a stream ofoxidizing gas. The regenerated catalyst is returned to the coversionstage of the process cycle. The enhanced thermal stability of ZSM-12 isadvantageous in this regard.

ZSM-12 zeolites can be used either in the alkali metal form, e.g., thesodium form; the ammonium form, the hydrogen form; or the multivalentforms or combinations of these forms are employed. They can also be usedin intimate combination with a hydrogenating component, such astungsten, vanadium, molybdenum, rhenium, nickel, cobalt, chromium,manganese, or a noble metal such as platinum or palladium where ahydrogenation or dehydrogenation function is to be performed. Suchcomponent can be exchanged into the composition, impregnated therein orphysically intimately admixed therewith. Such component can beimpregnated in or on to the ZSM-12 composition, such as, for example, inthe case of platinum, treating the composition with a platinummetal-containing ion. Thus, suitable platinum compounds includechloroplatinic acid, platinous chloride and various compounds containingthe platinum ammine complex.

The compounds of the useful platinum or other metals can be divided intocompounds in which the metal is present in the cation of the compoundand compounds in which it is present in the anion of the compound. Bothtypes of compounds which contain the metal in the ionic state can beused. A solution in which platinum metals are in the form of a cation orcation complex, e.g., [Pt(NH₃)₄ ]Cl₂, is particularly useful. For somehydrocarbon conversion processes, this noble metal form of the ZSM-12catalyst is unnecessary such as in low temperature, liquid phase orthoxylene isomerization.

When ZSM-12 is employed as an absorbent or as a catalyst in one of theaforementioned processes, partial dehydration of the ZSM-12 material isnecessary. This can be accomplished by heating to a temperature of about200° to about 600° C. in an atmosphere such as air, nitrogen or thelike, at atmospheric or subatmospheric pressures for between 1 and 48hours. Dehydration can also be performed at lower temperatures byplacing the ZSM-12 catalyst in a vacuum, however, a longer time isrequired to obtain a sufficient amount of dehydration.

The original cations of the as-synthesized ZSM-12 may be replaced atleast in part by other ions using conventional ion exchange techniques.It may be necessary to precalcine the ZSM-12 zeolite crystals prior toion exchange. The replacing ions introduced to replace the originalalkali, alkaline earth and/or organic cations may be any that aredesired so long as they can pass through the channels within the zeolitecrystals. The as-synthesized zeolite may be conveniently converted intothe hydrogen, the univalent or multivalent cationic forms by baseexchanging the zeolite to remove the sodium cations by such ions ashydrogen (from acids, ammonium, alkylammonium and arylammonium includingRNH₃, R₃ NH⁺, R₂ NH₂ and R₄ N⁺ where R is alkyl or aryl, provided thatsteric hindrance does not prevent the cations from entering the cage andcavity structure of the ZSM-12 type crystalline zeolite. The hydrogenform of the zeolite, useful in such hydrocarbon conversion processes asisomerization of poly-substituted alkyl aromatics and disproportionationof alkyl aromatics, is prepared, for example, by base exchanging thesodium form with, e.g., ammonium chloride or hydroxide, whereby theammonium ion is substituted for the sodium ion. The composition is thencalcined, at a temperature of, e.g., 1000° F. (about 540° C.), causingevolution of ammonia and retention of the hydrogen proton in thecomposition. Other replacing cations include cations of the metals ofthe Periodic Table, particularly metals other than sodium, mostpreferably metals of Group IIA, e.g., zinc, and Groups IIIA, IVA, IB,IIB, IIIB, IVB, VIB and Group VIIIA of the Periodic Table, and rareearth metals and manganese.

Ion exchange of the zeolite can be accomplished conventionally, e.g., bypacking the zeolite into a series of vertical fixed bed columns andsuccessively passing through the beds an aqueous solution of a solublesalt of the cation to be introduced into the zeolite, and then changingthe flow from the first bed to a succeeding one as the zeolite in thefirst bed becomes ion exchanged to the desired extent. Aqueous solutionsof mixtures of materials to replace the sodium can be employed. Forinstance, if desired, one can exchange the sodium with a solutioncontaining a number of rare earth metals suitably in the chloride form.Thus, a rare earth chloride solution commercially available can be usedto replace substantially all of the sodium in the as-synthesized ZSM-12zeolite. One such commercially available rare earth chloride solutioncontains chlorides of a rare earth mixture having the relativecomposition: cerium (as CeO₂) 48% by weight, lanthanum (as La₂ O₃) 24%by weight, praseodymium (as Pr₆ O₁₁) 5% by weight, neodymium (as Nd₂ O₃)17% by weight, samarium (as Sm₂ O₃) 3% by weight, gadolinium (as Gd₂ O₃)2% by weight, and other rare earth oxides 0.8% by weight. Another rareearth chloride mixture, which can also be used as an exchangingsolution, but has a lower cerium content, consists of the following rareearth metals determined as oxides: lanthanum 45-65% by weight, cerium1-2% by weight, praseodymium 9-10% by weight, neodymium 32-33% byweight, samarium 5-7% by weight, gadolinium 3-4% by weight, yttrium 0.4%by weight, and other rare earth metals 1-2% by weight. It is to beunderstood that other mixtures of rare earth metals are also applicablefor the preparation of the novel compositions of this invention,although cerium, lanthanum, neodymium, praseodymium, samarium andgadolinium as well as mixtures of rare earth cations containing apredominant amount of one or more of the above cations are preferred.

Base exchange with various metallic and non-metallic cations can becarried out according to the procedures described in U.S. Pat. Nos.3,140,251, 3,140,252 and 3,140,353, the entire contents of which areincorporated herein by reference.

Regardless of the cations replacing the alkali or alkaline earth metalsin the as-synthesized form of the ZSM-12, the spatial arrangement of thealuminum, silicon and oxygen atoms which form the basic crystal latticesof ZSM-12, remains essentially unchanged by the described replacement ofalkali or alkaline earth metal as determined by taking an X-ray powderdiffraction pattern of the ion-exchanged material. Such X-raydiffraction pattern of the ion-exchanged ZSM-12 reveals a patternsubstantially the same as that set forth in Table 2 above.

The aluminosilicates prepared by the instant invention are formed in awide variety of particle sizes. Generally speaking, the particles can bein the form of a powder, a granule, or a molded product, auch asextrudate having a particle size sufficient to pass through a 2 mesh(Tyler) screen and be retained on a 400 mesh (Tyler) screen. In caseswhere the catalyst is molded, such as by extrusion, the aluminosilicatecan be extruded before drying, or dried or partially dried and thenextruded.

In the case of many catalysts, it is desired to incorporate the ZSM-12with another material resistant to the temperatures and other conditionsemployed in organic conversion processes. Such materials include activeand inactive materials and synthetic or naturally occurring zeolites aswell as inorganic materials such as clays, silica and/or metal oxides.The latter may be either naturally occurring or in the form ofgelatinous precipitates or gels including mixtures of silica and metaloxides. Use of a material in conjunction with the ZSM-12, i.e., combinedtherewith which is active, tends to improve the conversion and/orselectivity of the catalyst in certain organic conversion processes.Inactive materials suitably serve as diluents to control the amount ofconversion in a given process so that products can be obtainedeconomically and orderly without employing other means for controllingthe rate of reaction. Normally, zeolite materials have been incorporatedinto naturally occurring clays, e.g., bentonite and kaolin, to improvethe crush strength of the catalyst under commercial operatingconditions. These materials, e.g., clays, oxides, function as bindersfor the catalyst. It is desirable to provide a catalyst having goodcrush strength, because in a petroleum refinery the catalyst is oftensubjected to rough handling, which tends to break the catalyst intopowder-like materials which cause problems in processing. Theaforementioned clay binders have been employed for the purpose ofimproving the crush strength of the catalyst.

Naturally occurring clays which can be composited with the ZSM-12catalyst include the montmorillonite and kaolin family, which familiesinclude the subbentonites, and the kaolins commonly known as DixieMcNamee-Georgia and Florida clays or others in which the main mineralconstituent is halloysite, kaolinite, dickite, nacrite, or anauxite.Such clays can be used in the raw state as originally mined or initiallysubjected to calcination, acid treatment or chemical modification.

In addition to the foregoing materials, the ZSM-12 catalyst can becomposited with a porous matrix material, such as silica-alumina,silica-magnesia, silica-zirconia, silica-thoria, silica-beryllia,silica-titania, as well as ternary compositions, such assilica-alumina-thoria, silica-alumina-zirconia, silica-alumina-magnesiaand silica-magnesia-zirconia. The matrix can be in the form of a cogel.The relative proportions of finely divided crystalline aluminosilicateZSM-12 and organic oxide gel matrix vary widely with the crystallinealuminosilicate content ranging from about 1 to 90 percent by weight andmore usually, particularly when the composite is prepared in the form ofbeads, in the range of about 2 to about 50 percent by weight of thecomposite.

Employing the ZSM-12 catalyst of this invention, containing ahydrogenation component, heavy petroleum residual stocks, cycle stocks,and other hydrocrackable charge stocks can be hydrocracked attemperatures between 400° F. and 825° F. using molar ratios of hydrogento hydrocarbon charge in the range of between 2 and 80. The pressureemployed varies between 10 and 2,500 psig and the liquid hourly spacevelocity between 0.1 and 10.

Employing the catalyst of this invention for catalytic cracking,hydrocarbon cracking stocks can be cracked at a liquid hourly spacevelocity between about 550° F. and 1,100° F., a pressure between aboutsubatmospheric and several hundred atmospheres.

Employing a catalytically active form of the ZSM-12 zeolite of thisinvention containing a hydrogenation component, reforming stocks can bereformed employing a temperature between 700° F. and 1,000° F. Thereforming process pressure is between 100 and 1,000 psig but ispreferably between 200 and 700 psig. The liquid hourly space velocity isgenerally between 0.1 and 10, preferably between 0.5 and 4 and thehydrogen to hydrocarbon mole ratio is generally between 1 and 20preferably between 4 and 12.

The catalyst can also be used for hydroisomerization of normalparaffins, when provided with a hydrogenation component, e.g., platinum.Hydroisomerization is carried out at a temperature between 200° and 700°F., preferably 300° to 550° F., with a liquid hourly space velocitybetween 0.01 and 2, preferably between 0.25 and 0.50 employing hydrogenso that the hydrogen to hydrocarbon mole ratio is between 1:1 and 5:1.Additionally, the catalyst can be used for olefin or aromaticisomerization employing temperatures between 30° F. and 500° F.

The catalyst may also be used for reducing the pour point of gas oils.This reduction is carried out at a liquid hourly space velocity betweenabout 10 and about 30 and a temperature between about 800° F. and about1,100° F.

Other reactions which can be accomplished employing the catalyst of thisinvention containing a metal, e.g., platinum, includehydrogenation-dehydrogenation reactions and desulfurization reactions.

In order to more fully illustrate the nature of the invention and themanner of practicing the same, the following examples are presented.

In the examples which follow whenever adsorption data is set forth itwas determined as follows:

A weighed sample of the zeolite was contacted with the desired pureadsorbate vapor in an adsorption chamber at a pressure less that thevapor-liquid equilibrium pressure of the absorbate at room temperature.This pressure was kept constant during the adsorption period which didnot exceed about eight hours. Adsorption was complete when a constantpressure in the adsorption chamber was maintained, i.e., 12 mm ofmercury for water and 20 mm for n-hexane and cyclohexane. The increasein weight in grams (g) per 100 g of calcined zeolite was calculated asthe adsorption capacity of the sample.

EXAMPLE 1 (Synthesis of DABCO-C₄ -diquat dibromide)

80 grams of 1,4-diazabicyclo[2,2,2]octane (DABCO) was dissolved in 100ml methanol and placed in a 1 liter round bottom flask equipped with amagnetic stirring bar, reflux-condenser, thermometer, and additionfunnel. 77.4 grams of 1,4-dibromobutane was added to the flask at such arate that the reaction temperature was maintained at 50±5° C. After theaddition of the 1,4-dibromobutane, the mixture was stirred at roomtemperature for 2 hours. Then, 300 ml of dry diethylether was added tothe flask and solid product (DABCO-C₄ -diquat dibromide) was filteredoff the reaction mixture.

EXAMPLE 2 (Synthesis of DABCO-C₅ -diquat dibromide)

80 grams of DABCO was dissolved in 100 ml methanol and placed in theapparatus of Example 1 above. 82.4 grams of 1,5-dibromopentane was addedto the flask at such a rate that the reaction temperature was maintainedat 50±5° C. After the addition of the 1,5-dibromopentane, the mixturewas stirred at room temperature for 2 hours. Then, 300 ml of drydiethylether was added to separate the DABCO-C₅ -diquat-dibromide as anoil from solvents. The lower layer (DIQUAT) was separated from the upperlayer (solvents) and evaporated to the solid product (DABCO-C₅ -diquatdibromide) by heating to 100° C. for 18 hours under vacuum (pressure ofabout 100 mm Hg).

EXAMPLE 3 (Synthesis of DABCO-C₆ -diquat dibromide)

80 grams of DABCO was dissolved in 100 ml methanol and placed in theapparatus of Example 1, above. 87.5 g of 1,6-dibromohexane was thenadded to the flask at such a rate that the reaction temperature wasmaintained at 50±5° C. Then, the reaction mixture was stirred for 2hours and 300 ml of dry diethylether was added to precipitate theproduct (DABCO-C₆ -diquat dibromide). If desired, the product could beisolated by filtration.

EXAMPLE 4 (Synthesis of DABCO-C₁₀ -diquat dibromide)

60 grams of DABCO was dissolved in 50 ml of methanol and placed in theapparatus of Example 1, above. A slurry of 25 ml methanol and 77.9 gramsof 1,10-dibromodecane was added to the flask at such a rate that thereaction temperature was maintained at 50±5° C. After the addition ofthe 1,10-dibromodecane, the reaction mixture was stirred at roomtemperature for 2 hours. Then, 250 ml of dry diethylether was added tothe reaction mixture, causing the product, DABCO-C₁₀ -dibromide, toseparate as an oil (bottom layer) from the solvents (top layer). Thebottom layer (oily product) was separated and 900 ml ofmethylethylketone was added thereto. This two phase mixture was thenstirred at room temperature until the product (DABCO-C₁₀ -diquatdibromide) crystallized and could be isolated by filtration.

EXAMPLE 5 (Synthesis of ZSM-12 with DABCO-C₅ -diquat dibromide)

0.8 g of aluminum nitrate, Al(NO₃)₃ 9H₂ O, was dissolved in 40 g ofwater. A solution of 10.55 g of DABCO-C₅ -diquat dibromide, produced inExample 2, in 50 g of water was added, followed by the addition of asolution of 3.1 g of sodium hydroxide (98%) in 25 g of water. Finally,24.0 g of Hi-Sil, a precipitated silica containing 87 wt % SiO₂, 6weight (wt) % free water (H₂ O) and 4.5 wt. % bound H₂ O of hydrationand having a particle size of 0.02 micron (μ), was added. The reactionmixture was heated in a Teflon-lined stainless steel autoclave at 160°C. and autogenous pressure for crystallization. After 299 hours at thistemperature a crystalline product was obtained. It was separated fromthe mother liquor by filtration, washed and dried at ambienttemperature.

The dried solid product had the X-ray diffraction pattern of ZSM-12 andhad a crystallinity of 100%, compared with a reference sample. Thesorptive capacities were, in g/100 g of solid at 25° C., aftercalcination in air at 550° C.:

Cyclohexane, at 20 Torr 7.9

n-Hexane, at 20 Torr 6.3

Water, at 12 Torr 6.9

The composition of the zeolite was in weight %:

SiO₂ (calculated by difference) 84.4

Al₂ O₃ 1.0

Na₂ O 0.78

N 1.88

Ash 86.2

SiO₂ /Al₂ O₃, molar ratio 145

The material exhibited the X-ray diffraction pattern essentially asshown below in Table III.

                  TABLE III                                                       ______________________________________                                                            RELATIVE INTENSITY                                        INTERPLANAR SPACING D(A)                                                                          100 I/I                                                   ______________________________________                                        11.95               13                                                        10.16               5                                                         6.16                2                                                         5.96                2                                                         4.71                12                                                        4.46                2                                                         4.26                100                                                       4.11                6                                                         3.96                12                                                        3.88                52                                                        3.76                3                                                         3.64                3                                                         3.46                18                                                        3.38                15                                                        3.20                6                                                         3.07                4                                                         3.03                2                                                         2.919               3                                                         2.879               3                                                         2.649               3                                                         2.589               2                                                         2.525               13                                                        2.472               4                                                         2.335               3                                                         2.053               6                                                         1.987               2                                                         1.951               4                                                         1.900               2                                                         1.851               2                                                         1.821               2                                                         ______________________________________                                    

Weak lines with intensities of less than 1.5 are not reported in TableIII. The abbreviations and symbols used in Table III have the samemeaning as those in Table II. Similarly, the data of Table III wasderived in the manner identical to that of the data in Table II.

EXAMPLE 6 (Synthesis of ZSM-12 with DABCO-C₁₀ -diquat dibromide)

The reaction mixture was the same as in Example 5, except that 12.2 g ofDABCO-C₁₀ -diquat dibromide was used instead of the corresponding C₅compound. After 253 hours at 160° C., a crystalline material having anaverage particle size of about 0.05×0.2μ was obtained. It was separatedfrom the mother liquor, washed and dried as in Example 5.

The dried solid had the X-ray diffraction pattern of ZSM-12,characteristic of small crystalline size and having a crystallinity ofabout 85%, measured by the peak heights. The sorptive capacities were,in g/100 g of solid at 25° C., after calcination in air at 550° C.:

Cyclohexane, at 20 Torr 7.0

n-Hexane, at 20 Torr 5.6

Water, at 12 Torr 5.5

EXAMPLE 7 (Synthesis of ZSM-12 with potassium and DABCO-C₁₀ -diquatdibromide)

The reaction mixture was the same as in Example 6, except that 4.0 g ofpotassium hydroxide, KOH, (86% KOH) was used instead of the 3.1 g ofsodium hydroxide, NaOH, (98% NaOH). After 367 hours at 160° C., acrystalline material was obtained, separated from the mother liquor,washed and dried as in Example 5.

The dried solid had the X-ray diffraction pattern of ZSM-12 and acrystallinity of 75%. The sorptive capacities were, in g/100 g of solidat 25° C., after calcination in air at 550° C.:

Cyclohexane, at 20 Torr 4.8

n-Hexane, at 20 Torr 4.7

Water, at 12 Torr 4.7

It will be apparent to those skilled in the art that the specificembodiments discussed above can be successfully repeated withingredients equivalent to those generically or specifically set forthabove and under variable process conditions.

From the foregoing specification, one skilled in the art can readilyascertain the essential features of this invention and without departingfrom the spirit and scope thereof can adapt it to various diverseapplications.

I claim:
 1. A process for preparing a siliceous porous crystallineZSM-12 zeolite material having the X-ray diffraction pattern of TableII, which comprises preparing a reaction mixture comprised of sources ofan alkali or alkaline earth metal, alumina, silica, RN⁺ and water, andhaving the following composition, in terms of mole ratios of oxides:OH⁻/YO₂ =0.10 to 0.40 RN⁺ /(RN⁺ +M)=0.2 to 0.95 H₂ O/OH⁻ =20 to 300 YO₂ /W₂O₃ =60 to 5000wherein Y is silicon or germanium, (RN)₂ ²⁺ is DABCO-C_(n)-diquat, having the formula: ##STR5## wherein n is 4-10, M is an alkalior alkaline earth metal, and W is aluminum or gallium, and maintainingthe mixture at crystallization conditions until crystals of said zeoliteare formed.
 2. A process of claim 1 wherein the mixture has thefollowing composition:OH⁻ /YO₂ =0.15 to 0.30 RN⁺ /(RN⁺ +M)=0.29 to 0.90H₂ O/OH⁻ =50 to 200 YO₂ /W₂ O₃ =60 to 500wherein Y, (RN)₂ ²⁺, M and Ware the same as in claim
 1. 3. A process of claim 2 wherein the mixturehas the following composition:OH⁻ /YO₂ =0.17 to 0.25 RN⁺ /(RN⁺ +M)=0.30to 0.50 H₂ O/OH⁻ =80 to 150 YO₂ /W₂ O₃ =90 to 300wherein Y, (RN)₂ ²⁺, Mand W are the same as in claim
 1. 4. A process of claim 3 wherein M ispotassium or sodium.
 5. A process of claim 4 wherein M is sodium.
 6. Aprocess of claim 5 wherein the DABCO-C_(n) -diquat is derived from thehalogen salt thereof, obtained by reacting two molecules ofdiazabicyclo(2,2,2)octane with one molecule of dihalo-n-alkane of theformula:

    X--(CH.sub.2).sub.n --X

wherein X is fluorine, chlorine, bromine or iodine and n=4-10.
 7. Aprocess of claim 6 wherein X is bromine.